The acquisition and description of a traffic situation is an essential task in the field of traffic telematics, the goal of which, for example, is to inform traffic participants about situations with traffic impediments and to rectify such situations and, if applicable, prevent them by appropriate predictive diversion of traffic participants onto less-crowded routes. Another task is that of determining information for traffic planning and road system planning.
A wide variety of approaches to determining traffic information is conventional. German Published Patent Application No. 195 08 486, for example, describes a method for determining traffic situation data or road status data in which individual random-sample vehicles, referred to as “floating cars,” transmit predetermined vehicle data and associated position data to a traffic control center. The traffic control center determines the traffic situation by the received data based on specific algorithms.
German Published Patent Application No. 195 21 919 describes a method for transmitting traffic situation information in which the vehicle and position data that are acquired are already allocated, in the vehicle operating as detector, to at least one predefined category of vehicle and position data that correspond to a specific typical vehicle behavior. These categories are referred to as “vehicle behavior patterns.” The associated vehicle behavior pattern is transferred with the position data of the vehicle, at least partially in coded form, to the traffic control center. European Published Patent Application No. 0 789 341 describes, in order to determine traffic situation information, to utilize the speed of the vehicle as vehicle data in the terminal of the mobile detector, by continuously acquiring it and evaluating it in the terminal by comparison with a limit speed as reference in the detector, so that when said speed falls below the limit speed, a change in traffic status lying below the threshold is recognized. The terminal, which is then in the evaluation state t\0, then checks the acquired speed values by comparison with the limit speed and, after a time t\0+t\1 has elapsed, interprets the overall traffic condition on the route segment as a traffic disruption if the mobile detector is being driven at a speed lower than the stored limit speed. If a traffic condition has been analyzed by the terminal as disrupted, an appropriate data telegram is generated and is transmitted via a mobile radio network to the traffic control center.
The disadvantage of conventional methods is principally that a large number of false and/or irrelevant messages are generated. In particular, long waits at traffic lights, barriers, etc. in urban areas, as well as deceleration actions before encountering rural population centers, are detected as traffic disruptions and are forwarded to customers.
It is an object of the present invention to provide the determination of traffic situation information so that the quantity of false and/or irrelevant traffic situation information may be further reduced, and an accurate picture of the traffic situation may be obtained.